Wing Vibration Research Articles

Visually induced initiation of Drosophila innate courtship-like following pursuit is mediated by central excitatory state.

The courtship ritual of male Drosophila represents an innate behaviour that is initiated by female-derived sensory stimuli. Here we report that moving light spots can induce courtship-like following pursuit in tethered wild-type male flies provided the fly is primed by optogenetic stimulation of specific dsx-expressing neuronal clusters in the lateral protocerebrum (LPR). Namely, stimulation of the pC1 neuronal cluster initiates unilateral wing extension and vibration of both sides, whereas stimulation of the pC2l cluster initiates only contralateral wing displays. In addition, stimulation of pC2l but not pC1 neurons induced abdominal bending and proboscis extension. Ca(2+) imaging of the pC1 cluster revealed periodic Ca(2+) rises, each corresponding to a turn of the male fly during courtship. In contrast, group-reared fru mutant males exhibit light spot-induced courtship pursuit without optogenetic priming. Ca(2+) imaging revealed enhanced responses of LPR neurons to visual stimuli in the mutants, suggesting a neural correlate of the light spot-induced courtship behaviour.

A mathematical model for the propulsive thrust of the thin elastic wing harmonically oscillating in a flow of non-viscous incompressible fluid

In the present paper there is proposed an analytical approach to study vibration of a rectangular elastic wing in the stationary stream of non-viscous fluid. We first develop a basic two-dimensional integral equation. Then a series expansion along the short coordinate is applied. This reduces the problem to an infinite set of one-dimensional integral equations which is studied asymptotically with respect to the large aspect ratio parameter. An example of optimization of thickness of the wing is demonstrated, to test the efficiency of the proposed method in applications.

Feeding and mating behaviour of Chinese citrus fly Bactrocera minax (Diptera, Tephritidae) in the field

The Chinese citrus fly, Bactrocera minax ,i s a major tephritid fruit fly pest that infests Citrus spp. fruits. The pest was removed from the national quarantine pest list in China in 2009 owing to its wide spread across the country, and it is currently considered a major threat to citrus industry in Asia. The frequent high infestation levels of B. minax in China emphasize the need for a more comprehensive understanding of its biology and ecology so that more effi- cient control measures can be developed and applied. In the framework of developing a sterile insect technique program against B. minax, we studied the feeding and mating activi- ties of B. minax in situ (Citrus orchards and surrounding habitats) through open field surveys and video recordings. In the pre-oviposition period, sexually immature adults largely foraged for food (e.g. honeydew from aphids, nectar and sooty mould) on non-host plants. Then, sexually mature adult flies shifted to lick sooty moulds, bird faeces and, to a lesser extent, an unknown substance on the Citrus leaves and fruits during the mating and oviposition periods. Finally, during the post-oviposition period, the flies were observed feeding on ooze from grapes. The mating behaviour patterns of B. minax in the field were described as follows: first, the male established its territory close to the potential oviposi- tion substrate (Citrus fruit), second, the female landed on the fruit and began inspection and ovipositor boring behaviour on the fruit surface (no male courtship observed e.g. wing vibration), and third, the male mounted and copulated with the female. The present study shed light on the feeding ecology and mating behaviour of B. minax in the field; this knowledge will facilitate development of better management strategies against this tephritid fly.

Ordered randomness in fly love songs

A systematic and painstaking analysis reveals that much of the complexity and variability of the courtship song of male fruit flies can be accounted for by simple rules that relate sensory experience to motor output. See Letter p.233 Males in many animal species produce patterned courtship songs to increase reproductive success with females, so variations in song structure have been seen as detrimental 'noise'. Drosophila melanogaster males use courtship song, generated by wing vibrations, and Mala Murthy and colleagues have studied the patterning of these signals. They find that males adjust the pattern of their songs, constructed of two alternating song modes, according to visual and self-motion sensory inputs. Females are sensitive to these efforts, and change their walking speed according their behavioural state and the song's features. The results contradict a widespread assumption that courtship songs follow a fixed pattern, and establish Drosophila as a promising experimental model to study rapid decision-making in a complex social environment.

Mutations of the Drosophila Myosin Regulatory Light Chain Affect Courtship Song and Reduce Reproductive Success

The Drosophila indirect flight muscles (IFM) rely on an enhanced stretch-activation response to generate high power output for flight. The IFM is neurally activated during the male courtship song, but its role, if any, in generating the small amplitude wing vibrations that produce the song is not known. Here, we examined the courtship song properties and mating behavior of three mutant strains of the myosin regulatory light chain (DMLC2) that are known to affect IFM contractile properties and impair flight: (i) Dmlc2Δ2–46 (Ext), an N-terminal extension truncation; (ii) Dmlc2S66A,S67A (Phos), a disruption of two MLC kinase phosphorylation sites; and (iii) Dmlc2Δ2–46;S66A,S67A (Dual), expressing both mutations. Our results show that the Dmlc2 gene is pleiotropic and that mutations that have a profound effect on flight mechanics (Phos and Dual) have minimal effects on courtship song. None of the mutations affect interpulse interval (IPI), a determinant of species-specific song, and intrapulse frequency (IPF) compared to Control (Dmlc2+ rescued null strain). However, abnormalities in the sine song (increased frequency) and the pulse song (increased cycles per pulse and pulse length) evident in Ext males are not apparent in Dual males suggesting that Ext and Phos interact differently in song and flight mechanics, given their known additive effect on the latter. All three mutant males produce a less vigorous pulse song and exhibit impaired mating behavior compared to Control males. As a result, females are less receptive to Ext, Phos, and Dual males when a Control male is present. These results open the possibility that DMLC2, and perhaps contractile protein genes in general, are partly under sexual selection. That mutations in DMLC2 manifest differently in song and flight suggest that this protein fulfills different roles in song and flight and that stretch activation plays a smaller role in song production than in flight.

超音波がハスモンヨトウの求愛行動（羽ばたき）に及ぼす影響

超音波がハスモンヨトウの求愛行動（羽ばたき）に及ぼす影響

Courtship Patterns in theDrosophila montiumSpecies Subgroup: Repeated Loss of Precopulatory Courtship?

During precopulatory courtship, male Drosophila typically produce wing vibration to generate species-specific songs before mounting females. Three species in the lini clade of the montium species subgroup have been found to produce species-specific sine song only after mounting and during copulation. Here we investigated and analyzed the courtship behavior of 29 species in the montium subgroup from video and song recordings and measured the duration of wing vibration. We describe a great diversity of courtship behavior in the montium subgroup. The courtship patterns can be categorized into four types in the montium subgroup: 1) type P/C, species with both precopulatory and copulatory courtship, such as D. parvula and D. nikananu, 2) type P-/C, species with sporadic precopulatory and mainly copulatory courtship, such as D. auraria and D. triauraria. 3) type C, species with only copulatory courtship, such as D. tani and D. pectinifera, 4) type C-, species with only very brief copulatory courtship, such as D. rufa and D. asahinai. According to a phylogenetic tree based on sequences of mitochondrial COI and COII, and the nuclear Adh, both precopulatory courtship and copulatory courtship were present in the most basal species D. parvula. Each of two branches in the montium subgroup contains four types of courtship behavior. Type C is present in each sub-branch. These results suggest that the courtship behavior initially involved both precopulatory and copulatory courtship, but that subsequently precopulatory courtship has gradually been lost in the montium subgroup. We suggest reasons why precopulatory behavior might come to be lost in the montium subgroup.

Thin-Wing Vibration Control Using Flexible Fins

This paper describes thin-wing vibration control using an array of small flexible rectangular polymer fins attached near the leading edge on the upper wing surface to manipulate unsteady flow structures. Dynamic aeroelastic deformation of a rectangular flat-plate wing and motions of the fins relative to the wing are measured by using a high-speed videogrammetric system in a low-speed wind tunnel. The major vibration modes of the baseline wing and the wing with the fins are extracted. It is found that wing vibration particularly near the dominant first torsion mode is considerably suppressed by the flexible fins interacting with highly unsteady separated flows in the ranges of the freestream velocities and angles of attack. Global velocity measurements indicate that the fins significantly reduce the unsteadiness of the separated flow on the wing. The physical mechanisms behind the vibration suppression with the flexible fins are explored based on the analysis of the measured data.

Female-Released Sex Pheromones Mediating Courtship Behavior inLysiphlebus testaceipesMales

Ethological aspects and chemical communication at close-range between the sexes of Lysiphlebus testaceipes Cresson (Hymenoptera: Braconidae) have been investigated through behavioral bioassays and chemical analysis. The attractiveness toward males of whole-body extracts of females and males in hexane and acetone was evaluated, adopting male fanning behavior as a key behavioral component. Also, the activity of polar and nonpolar fraction of female-body extract in hexane obtained using solid-phase extraction technique was investigated. In order to identify cuticular compounds, male and female whole-body extracts with hexane and acetone were analyzed by gas chromatography-mass spectrometry. The results showed that males exhibit a behavior including 4 phases when exposed to virgin females: premount, mount, copulation, and post-copulation. A preliminary courtship of the male included wing fanning, an extension and vibration of the wings for 1 to 2 seconds. Also, some original aspects not described for other species were carried out. The average duration of the entire sequence of events was 138.80 ± 19.51 sec. Also, males displayed significantly more wing fanning behavior in response to female whole-body hexane extracts (70.83%) than female whole-body acetone extracts (33.3%). Furthermore, males did not respond to male-body extracts or to the control (pure hexane and acetone), suggesting that the sex pheromone is composed of cuticular hydrocarbons that are also involved in the male courtship behavior. When hexane extracts of whole females were fractionated on silica gel and exposed to males, more activity was recorded for the nonpolar fraction (50.0%) than the polar fraction (27.7%), but no significant statistical difference was found. Significant differences were detected comparing the control (not fractionated extract) with the polar fraction, but not with the nonpolar fraction. A homologous series of n-alkanes with chain lengths from C19 to C30 carbon atoms was identified and quantified in the solvent extracts of wasp males and females. Between male and female extracts, there was a statistically significant difference in the average quantity of some of these hydrocarbons, such as C27, C28, and C29.

Self-cleaning of superhydrophobic surfaces by self-propelled jumping condensate

The self-cleaning function of superhydrophobic surfaces is conventionally attributed to the removal of contaminating particles by impacting or rolling water droplets, which implies the action of external forces such as gravity. Here, we demonstrate a unique self-cleaning mechanism whereby the contaminated superhydrophobic surface is exposed to condensing water vapor, and the contaminants are autonomously removed by the self-propelled jumping motion of the resulting liquid condensate, which partially covers or fully encloses the contaminating particles. The jumping motion off the superhydrophobic surface is powered by the surface energy released upon coalescence of the condensed water phase around the contaminants. The jumping-condensate mechanism is shown to spontaneously clean superhydrophobic cicada wings, where the contaminating particles cannot be removed by gravity, wing vibration, or wind flow. Our findings offer insights for the development of self-cleaning materials.

Receptivity of the boundary layer to vibrations of the wing surface

AbstractIn this paper we study the generation of Tollmien–Schlichting waves in the boundary layer due to elastic vibrations of the wing surface. The subsonic flow regime is considered with the Mach number outside the boundary layer $M= O(1)$. The flow is investigated based on the asymptotic analysis of the Navier–Stokes equations at large values of the Reynolds number, $\mathit{Re}= {\rho }_{\infty } {V}_{\infty } L/ {\mu }_{\infty } $. Here $L$ denotes the wing section chord; and ${V}_{\infty } $, ${\rho }_{\infty } $ and ${\mu }_{\infty } $ are the free stream velocity, air density and dynamic viscosity, respectively. We assume that in the spectrum of the wing vibrations there is a harmonic that comes in to resonance with the Tollmien–Schlichting wave on the lower branch of the stability curve; this happens when the frequency of the harmonic is a quantity of the order of $({V}_{\infty } / L){\mathit{Re}}^{1/ 4} $. The wavelength, $\ell $, of the elastic vibrations of the wing is assumed to be $\ell \sim L{\mathit{Re}}^{- 1/ 8} $, which has been found to represent a ‘distinguished limit’ in the theory. Still, the results of the analysis are applicable for $\ell \gg L{\mathit{Re}}^{- 1/ 8} $ and $\ell \ll L{\mathit{Re}}^{- 1/ 8} $; the former includes an important case when $\ell = O(L)$. We found that the vibrations of the wing surface produce pressure perturbations in the flow outside the boundary layer, which can be calculated with the help of the ‘piston theory’, which remains valid provided that the Mach number, $M$, is large as compared to ${\mathit{Re}}^{- 1/ 4} $. As the pressure perturbations penetrate into the boundary layer, a Stokes layer forms on the wing surface; its thickness is estimated as a quantity of the order of ${\mathit{Re}}^{- 5/ 8} $. When $\ell = O({\mathit{Re}}^{- 1/ 8} )$ or $\ell \gg {\mathit{Re}}^{- 1/ 8} $, the solution in the Stokes layer appears to be influenced significantly by the compressibility of the flow. The Stokes layer on its own is incapable of producing the Tollmien–Schlichting waves. The reason is that the characteristic wavelength of the perturbation field in the Stokes layer is much larger than that of the Tollmien–Schlichting wave. However, the situation changes when the Stokes layer encounters a wall roughness, which are plentiful in real aerodynamic flows. If the longitudinal extent of the roughness is a quantity of the order of ${\mathit{Re}}^{- 3/ 8} $, then efficient generation of the Tollmien–Schlichting waves becomes possible. In this paper we restrict our attention to the case when the Stokes layer interacts with an isolated roughness. The flow near the roughness is described by the triple-deck theory. The solution of the triple-deck problem can be found in an analytic form. Our main concern is with the flow behaviour downstream of the roughness and, in particular, with the amplitude of the generated Tollmien–Schlichting waves.

Neuroendocrine mechanisms underlying regulation of mating flight behaviors in male honey bees (Apis mellifera L.)

We determined the neuroendocrine mechanisms underlying regulation of mating flight behaviors in male honey bees. Both a precursor of dopamine (3,4-dihydroxyphenylalanine: DOPA) and a precursor of octopamine (tyramine) in the brain decreased in an age-dependent fashion before sexual maturation (i.e. 8days of age), whereas the levels of brain dopamine, dopamine metabolites (N-acetyldopamine and norepinephrine) and octopamine were increased. These age-dependent increases of dopamine and octopamine were also detected in the meso-metathoracic ganglia. Injection of either dopamine or octopamine into 7–8-day-old males shortened the duration for flight-initiation and increased the duration of wing vibration, indicating that both dopamine and octopamine enhance the flight-initiation and -sustaining activities in males. Applications of a juvenile hormone analog (methoprene) enhanced the levels of dopamine in the brains of 4-day-old males, but this enhancement was not detected in either brain octopamine or meso-metathoracic dopamine and octopamine. Thus, we found that both dopamine and octopamine in the brain and meso-metathoracic ganglia increase until sexual maturation and could enhance the activities of mating flight independently; in addition, the increase in levels of dopamine in the brain could be selectively regulated by juvenile hormone. The regulatory systems of dopamine and octopamine in honey bee males might be ‘classical’ and similar to those of primitively eusocial hymenopterans, and partly adapt to the short lifespan with a single mating system in the males.

Analysis of courtship behavior in closely related species of Drosophila virilis group: a new approach arises new questions

Courtship behavior of males was studied in four closely related Drosophila species: D. virilis, D. lummei, D. a. americana and D. littoralis. Using a video-computing approach, we compared behavior in males courting conspecific and heterospecific females. In males of all species studied, touching and licking were found to be the most prolonged courtship elements. Touching and licking were typically proceeding together; wing vibration was usually produced against a background of touching and licking. We found only minor interspecific variations in courtship rituals. Heterospecific courtships in D. virilis and D. lummei were almost as active as conspecific ones; however, isolation between D. a. americana and D. littoralis appeared to be much stronger than between D. virilis and D. lummei. Analysis of prolonged touching and licking raises a question about chemical and tactile sensory stimuli exchanged between sexes in the developed courtship of D. virilis group.

Male Wing Fanning Performance During Successful and Unsuccessful Mating in the Parasitic Wasp Lariophagus distinguendus Förster (Hymenoptera: Pteromalidae)

Lariophagus distinguendus Forster (Hymenoptera: Pteromalidae) is a generalist solitary ectoparasitoid that parasitizes the immature stages of at least 11 foodstuff beetles from five families, including species developing in the seeds of Poaceae, Fabaceae and in dried natural products. In L. distinguendus, male wing fanning is a key phase in the courtship sequence and is elicited by a female-borne sex pheromone. However, studies aimed at understanding the role of wing vibration in L. distinguendus during courtship are lacking. In this research, the wing fanning performances of the L. distinguendus male towards other females and males were analyzed through high-speed video recordings and examined in relation to mating success. Only small differences were found between the fanning characteristics displayed toward females and young males, highlighting that young males are really perceived as females by older males. Male mating success was affected by the quality of the wing fanning in the courtship phase. Indeed, both immediately after the female perception and during mating attempts, fanning before a successful courtship differed compared to wing fanning performed prior to an unsuccessful courtship in terms of their mean frequency, but not their amplitude. Overall, our work increases knowledge of the courtship behavior of L. distinguendus and highlights the crucial importance of wing fanning among the range of sensory modalities used in the sexual communication of this parasitic wasp.

The production of female sex pheromone in Bactrocera oleae (Rossi) young males does not influence their mating chances

AbstractIn Bactrocera oleae females attract males, which is in contrast to the majority of Tephritidae. However, the major component of the secretion of the female rectal ampulla glands, 1,7‐dioxaspiro‐[5,5]‐undecane (DSU), was also isolated from the glands of young males. The DSU produced by females and young males attracts males, but not females. In this study, we investigated the role of the production of DSU in young males. The mating performances of young and old males were evaluated, as well as the male‐male courtships by old males oriented at young and old males. Young males were found not to have a mating advantage. Young males were courted more by other males. Frame‐by‐frame analysis of male wing vibrations showed that this behavior did not differ when oriented at females and young males, highlighting that young males are perceived as females by the courting males. Overall, the production of DSU in young B. oleae males did not seem to be a case of female chemical mimicry. The hypothesis that young olive fruit fly males could benefit indirectly from the DSU production, simply distracting mature males away from females, is discussed.

Effect of Drosophila melanogaster Female Size on Male Mating Success

In this study, we examined the influence of female size on mating success in Drosophila melanogaster. The results that were obtained from experiments performed in mating chambers allowed us to confirm the results of previous studies, demonstrating higher mating success of larger D. melanogaster males, and to conclude that female size also affects mating success, either when considering a single male or two competing males. We observed that the advantage for larger males depends on their size relative to that of the female, demonstrating a previously unknown role for female size in mating behavior studies. This effect of female size on mating success depends on various factors: males take longer to initiate courtship toward larger females, large females receive more wing vibrations from males prior to mating, and large females tend to keep moving for longer periods during male courtship. The importance of this finding is discussed in the context of recent reports on sexual conflict in D. melanogaster, in which males were observed to depress fitness in females as a result of intercourse.

Male Wing Vibration in the Mating Behavior of the Olive Fruit Fly Bactrocera oleae (Rossi) (Diptera: Tephritidae)

The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae), is a worldwide pest of olive fruits. To date, the mating behavior of this tephritid has not been fully clarified. Little has been reported regarding the characteristics and behavioral role of B. oleae male wing vibration. This study provides a detailed description of male wing vibration, recorded by a high-speed video camera and compared with a frame-by-frame analysis, prior to successful and unsuccessful matings. Experimental evidence is given of the importance of male wing vibration during courtship for successful mating. Firstly, when the males did not perform wing vibration, but simply jumped onto the female and immediately attempted to copulate, no successful matings were registered. Secondly, when the male’s wings were removed, the probability of successful mating was significantly reduced. Thirdly, the frequency and pulse duration of the male wing vibration during courtship were higher in successful matings than in unsuccessful ones. Lastly, a wing sexual dimorphism was found: length and total wing area were significantly higher among males. Overall, our research increases the knowledge of the reproductive behavior of B. oleae, by suggesting the importance of wing vibration among the range of sensory modalities used by this tephritid in sexual communication.

Multibody simulation of a generalized predictive controller for tiltrotor active aeroelastic control

A generalized predictive control has been developed for the control of the aeroelasticity and structural dynamics of a tiltrotor. Adaptivity is the key feature of the proposed technique. It gives the controller the capability to autonomously follow the variations of the system. A comprehensive simulation system has been adopted to design and test the adaptive regulator under realistic conditions. The aeroservoelastic tiltrotor has been modelled using a multibody approach, considering the structural dynamics, the aerodynamics, the blade pitch control system kinematics, and actuator and sensor dynamics. Numerical simulations illustrate the capability of the adaptive controller to reduce wing vibrations and loads while significantly extending the flutter-free flight envelope. This controller shows satisfactory performances within the whole flight envelope as it is able to properly work in different rotor trim conditions and varying structural properties in the presence of external disturbances and measurement noise.

Neural Network Recognizes Fruit Fly's Wing Vibration Sound Based on Hilbert-Huang Transform

The paper applies Hilbert-Huang Transform to process the fruit fly’s wing vibration sound. Firstly, it gets Hilbert-Huang spectrum and marginal spectrum of the wing vibration sound of two different strains of fruit fly in the same species. Then, it analyzes differences of the energy size and the energy distribution, and extracts features including the relative energy, time-frequency entropy and the cumulated amplitude value of marginal spectrum. Finally, recognizes two different strains of fruit fly by BP neural network and obtains a satisfying result. The experiment result verifies effectiveness and feasibility of the feature extraction, and the paper offers a new evidence for the study of discrimination in intraspecies relationship of fruit fly.

Different sensory modalities are required for successful courtship in two species of the Drosophila willistoni group

During courtship, specific signals are transmitted and received between the male and the female. To understand the evolution and function of courtship behaviours, these signals must be tested individually to determine their relative effects. Drosophila species have a variety of courtship patterns that use different sensory modalities, including chemosensory, tactile, visual and auditory cues, and thus provide an opportunity for exploring different sensory modalities. In most species of the Drosophila willistoni group, males produce an auditory cue (courtship song) through wing vibration. One species, Drosophila nebulosa, does not produce an auditory signal in courtship, although both sexes perform wing-lifting movements and males fan an anal droplet towards the female. We compared the sensory modalities important for mating success in D. nebulosa and D. willistoni through a series of phenotypic manipulation experiments in which individuals had disrupted transmission or reception of signals. In D. nebulosa, females had to be able to smell, presumably to detect the anal droplet, for successful mating to occur, whereas for males of the same species, vision was essential. In contrast, no single sensory modality was absolutely necessary for D. willistoni mating success, although hearing greatly increased mating success for females and courtship song greatly increased mating success for males. Thus, these species are divergent in the sensory modalities necessary for courtship success, indicating that courtship behaviour may change rapidly within species groups.